Meet the site
Olwolgin Cave is the modern headline of Nullarbor cave diving. Exploration began in 2001 under Paul Hosie, and major underwater passages were discovered in 2011. By January 2015 more than 11,000 m of passage had been surveyed in the downstream sector, making it Australia's longest known underwater cave system. The passages are shallow – about 10 m beneath the surface – and include named sections such as Grand Central (130 m long, 30 m wide), Babylon Lake with its 'hanging gardens', and Blood Moon Passage. Divers report white-coated walls, organic growth mats, toxic atmospheres in air spaces and an ancient dingo skeleton on a passage floor.
The entry is comparatively easy – a 1.3 km bush walk to a small daylight pool – but the diving is extreme: exploration uses sidemount rebreathers with bailout, with dives lasting more than four hours away from base. The CDAA rates Olwolgin Advanced Cave. It offers immense scope for scientific research, and exploration is far from complete.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Olwolgin Cave is recorded as Cave/Cavern in Nullarbor Caves. The listed access is shore. Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Lines and obstructions
- Discuss any known entanglement concerns and the suitability of the planned area.
- Overhead environments
- Ask whether the plan stays entirely in open water. A wreck or cave listing is not permission or training to enter.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is Olwolgin Cave suitable for my certification?
The record lists Cave/Cavern certification. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book Olwolgin Cave through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Stygofauna; organic growth mats; bacterial coatings
Location
Shallow phreatic cave system on the Roe Plain, explored from 2001 and with major discoveries from 2011; with more than 11 km surveyed downstream it is Australia's longest known underwater cave. CDAA Advanced Cave.
Facilities nearby
None; nearest roadhouses on the Eyre Highway.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
divernet.comen.wikipedia.orgRecord updated 26 Sept 2026. Source claims are being reviewed.